Flow-through heater

ABSTRACT

A flow-through heater includes a heating element and a liquid-bearing tube connected to the heating element. The liquid-bearing tube has a flat area on which a thermostat is mounted.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority of German Patent Application No. 202007 002 963.2 filed on Feb. 27, 2007, the subject matter of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION

The invention relates to a flow-through or continuous-flow heater, usedin particular for coffee machines. Such a heater includes aliquid-bearing tube of a heat-conducting material which is connected toa heating element.

Flow-through water heaters for coffee machines are known, for which thebrewing water inside a heating tube is heated with the aid of a tubularheating element, arranged adjacent thereto, and is then released in theheated state via a spray nozzle. To avoid overheating, a thermostat witha contact disk is attached to the heating tube, wherein a bracket iseither welded on or press fitted to the heating tube to obtain asufficiently flat connection with the contact disk. This additionaloperational step of welding on or press-fitting to the bracket is notonly expensive, but also results in or creates insufficiently flatcontact areas. Further, the known flow-through heaters have a limitedcapacity for storing energy.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to create aflow-through heater which is easy to produce and makes optimum use ofheat energy.

The above and other objects are accomplished according to the inventionby the provision of a flow-through heater, which in one embodimentincludes: a heating element; a liquid-bearing tube connected to theheating element, the liquid-bearing tube having a flat area; and athermostat mounted on the flat area of the liquid-bearing tube.

Accordingly, in the above embodiment of the invention, theliquid-bearing tube has a flat area on which a thermostat is mounted. Asa result, the flow-through heater can be installed without theinstallation step of press-fitting the heating tube, since the flatsurface is already formed-on during the production, for example duringthe process of extruding the tube.

According to a further embodiment, the flat area is arranged on aninside region of the bow-shaped, curved flow-through heater. Thethermostat is also arranged on the inside of the curve, thereby ensuringa compact design.

The flat area on the liquid-bearing tube may be formed by two materialenlargements forming corner regions, which are then available asadditional energy storage areas. The liquid-bearing tube, which may bearranged adjacent to the flat area and the material enlargements, may beembodied with a generally ring-shaped cross section and uniform wallthickness, so that the tube remains flexible and the materialexpenditure is limited.

According to another embodiment of the invention, the liquid-bearingtube and the housing for the heating element are linked by a connectingweb to ensure good conductivity. The liquid-bearing tube and the housingfor the heating element can thus be produced integrally of a metal,preferably an extruded aluminum profile, which makes possible anespecially easy installation of the unit consisting of the heatingelement and liquid-bearing tube.

In a further embodiment according to the invention, a materialenlargement is provided as an energy store on the heating element forthe flow-through heater, on the side facing the fluid-bearing tube. As aresult, the heating intervals of the heating element can be extended,which prolongs the service life.

The material enlargement advantageously forms a flat area on one side ofthe heating element, which extends parallel to a flat area on theliquid-bearing tube with the thermostat. In particular, the two flatareas may be arranged in a joint plane.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the invention will be furtherunderstood from the following detailed description, with reference tothe accompanying drawings.

FIG. 1 shows a side view of a flow-through heater according to theinvention, in an assembled state.

FIG. 2 shows a sectional view of a detail of the heating element and theliquid-bearing tube.

FIG. 3 shows a view of a detail showing the thermostat on theliquid-bearing tube.

DETAILED DESCRIPTION

Referring to FIG. 1, there is shown a flow-through heater 1 for a carafe2 for keeping a brewed beverage warm, especially coffee, wherein thiscarafe rests with its bottom 3 on a heating plate 4. Arranged underneaththe heating plate 4 is a body 5, comprising a heating element 6 and aliquid-bearing tube 7, which are connected to each other via anintegrally formed connecting web 8. The body 5 serves as heat conductorand energy store, so that the heating plate 4 is heated up at the sametime as the heating element 6, which heats up the water inside theliquid-bearing tube 7. The body 5 in this case takes the shape of ahorseshoe and is arranged at least in the region below the heating plate4, wherein the body 5 can also have a meandering shape.

The body 5 is formed with an extruded aluminum profile, which isinitially produced as a straight profile and is then bent into shape.

FIG. 2 represents a cross section through the body 5. The heatingelement 6 consists of an electric resistance wire that is enclosed by aninsulating material 14 and a sleeve 13, preferably a copper tube. Heatis released via the heating element 6 to a housing 12, formed by thebody 5.

A flat area 9, against which the heating plate 4 rests, is embodied onthe side of the heating element 6 that is facing away the liquid-bearingtube 7.

A material enlargement 20 is furthermore provided as an energy store onthe heating element 6, on the side facing the liquid-bearing tube 7. Thematerial enlargement 20 forms a flat area 10 on an inside region of thebody 5.

Body 5 includes another flat area 11 adjacent to the liquid-bearing tube7. A thermostat 17 is mounted on flat area 11 via a flat disk 18 (seeFIG. 3). Once the heating element 6 is heated up, the body 5 warms upand heat energy is conducted via a connecting web 8 to theliquid-bearing tube 7. If the liquid-bearing tube 7 does not contain anywater for cooling, then steps must be taken to prevent a further heatingup of the flow-through heater. This is achieved with the thermostat 17,which contains a bimetallic element that is automatically deformedmechanically upon reaching a specific temperature, which results indisconnecting the electric circuit. The heating element 6 is thereforeturned off once a specific temperature is reached, until the bimetallicelement has regained its original shape, following a cooling down.

For the embodiment shown herein, the heating element 6 is arrangedbetween the heating plate 4 and the liquid-bearing tube 7. Of course,the heating element 6 and the tube 7 can also be arranged horizontallyside-by-side instead of vertically one above the other.

The heating element 6 includes a material enlargement 20 arrangedadjacent to the liquid-bearing tube 7 that serves as supplementary heatstore or heat reservoir. It is also possible to provide several materialenlargements, for example in the form of ribs, on the housing 20 for theheating element 6.

It will be understood that the above description of the presentinvention is susceptible to various modifications, changes andadaptations, and that the same are intended to be comprehended withinthe meaning and range of equivalents of the appended claims.

1. A flow-through heater, comprising: a body having a first portion, asecond portion defining a liquid-bearing tube, and a connecting web toconnect the first and second portions, wherein the liquid-bearing tubehas a flat area; a heating element embedded in the first portion of thebody; and a thermostat mounted on the flat area of the liquid-bearingtube, wherein the first portion of the body includes a materialenlargement constituting an energy store on a side facing theliquid-bearing tube.
 2. The flow-through heater according to claim 1,wherein flow-through heater has a curved shape and the flat area islocated on an inside area of the curved shaped flow-heater.
 3. Theflow-through heater according to claim 1, wherein the liquid-bearingtube has a generally ring-shaped cross section with a uniform wallthickness and including two material enlargements comprising cornerregions defining the flat area, the liquid-bearing tube being arrangedadjacent to the flat area and the material enlargements.
 4. Theflow-through heater according to claim 1, wherein the first portion, theliquid-bearing tube and the connecting web comprise an integral metalbody.
 5. The flow-through heater according to claim 4, wherein theintegral metal body comprises aluminum.
 6. The flow-through heateraccording to claim 1, wherein the material enlargement includes a flatarea which extends parallel to the flat area on the liquid-bearing tubeon which the thermostat is mounted.
 7. The flow-through heater accordingto claim 6 wherein the flat area resulting from the material enlargementon the first portion and the flat area on the liquid-bearing tube, onwhich the thermostat is mounted, are arranged in a single plane.